When cleaning teeth and prosthodontic structures, dental practitioners often use commonly known disposable fittings for a power dental hand piece. These fittings have, on an output end, a cup capable of holding an abrasive polishing substance. The cup is rotated by the powered hand piece and through the disposable fittings. This allows the cup to apply the polishing substance and also perform the polishing function. After use on a patient, the fittings are disposed of.
One commonly known disposable fitting would benefit from improvement in a variety of ways. Most attachments to a dental hand piece rotate in a single direction of rotation. The commonly known disposable fitting, by design, always rotates counter to this common standard. This anomaly causes dental practitioners to compensate when using the apparatus, since rotational forces created by impacting the cup against the structures to be cleaned create "drift" which is always opposite from that anticipated by dental practitioners accustomed to ordinary hand piece attachments. To compensate, the practitioner can alter the drill rotation pneumatically but this requires subsequent reversion when another tool is used on the drill.
Furthermore, in assembling the commonly known disposable fitting, an integrally molded door is included which holds both of the gears of the fitting in close contact. This door being hinged only by a thin portion of plastic, requires critical engineering surveillance regarding cycle time and plastic recycling content because its elasticity is critical.
This invention solves the above and other problems in a new and useful way. It has an anticipated direction of rotation and has a means for holding the gears in place which is more easily manufactured and therefore provides even greater durability.
The following patents reflect the state of the art of which applicant is aware and are included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that these references taken alone or in any conceivable combination do not teach the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________ INVENTOR PATENT NO. ISSUE DATE ______________________________________ A. M. Goldenberg 2,300,828 November 3, 1942 J. C. Shotton 2,315,016 March 30, 1943 H. D. Greenberg 2,328,270 August 31, 1943 A. D. Wiseman 3,163,934 January 5, 1965 E. Hoffmeister et al. 3,229,369 January 18, 1966 Graham 3,727,313 April 17, 1973 ______________________________________
The Graham patent is of interest in that it teaches a disposable prophylaxis fitting for a dental hand piece comprised of a long gear and a short gear. However, the Graham patent teaches a gear interface on the exterior of the angle formed by the longitudinal axes of the two gears, rather than on the interior of that angle as does the applicant's instant device. Applicant's device thus spins in an opposite direction from the device of Graham when both devices receive an input of similar direction. Furthermore, applicant's device employs a means of long gear retention which improves on that taught by the Graham patent. Other structural distinctions and benefits result from these differences.
The Wiseman patent teaches a Dental prophylaxis right angle hand piece which is designed for removal and sterilization for re-use. The applicant's device is significantly different from Wiseman in that the applicant's device is disposable. This attribute allows for low cost manufacture and improved sanitation through only single use of the device.
The applicant's device is distinguishable from the Goldenberg patent in that the Goldenberg patent teaches an automatic feed of polishing compound to a tip of the hand piece. The Goldenberg patent also is designed to interface with a dental drill, not just a dental hand piece as does the applicant's. The remainder of the prior art cited above perform functions other than dental prophylaxis.
These other patents also are not designed to be disposable. Thus, the applicant's invention is distinguishable from these other prior art patents.